This invention describes an oil filter wrench for installing and removing filter cartridges in limited access locations on automobiles and the like.
There are many versions of oil filter wrenches currently available, the most popular of which provides a strap for encircling the filter cartridge and a handle for tightening the strap and providing torque thereto. The strap form of tool is inexpensive and advantageous in that it spreads the gripping force about the complete periphery of the cartridge and can achieve the necessary gripping force without damaging the typical thin sheet metal container of most filter cartridges. This form of tool is also convenient in that it can accommodate a fairly wide range of cartridge sizes. Recently however, engine compartments have become more crowded and it is difficult to maneuver this type of tool both in gaining access to the cartridge and applying the necessary torque thereto.
Other forms of tools have been devised to accommodate this situation. One form is described in U.S. Pat. No. 3,119,290 wherein a socket-like tool is provided for accessing the filter cartridge axially, similar to a socket wrench and where torque is applied generally along the axis of the filter cartridge, rather than at the periphery in the strap type of tool. In the socket form of tool described, the socket portion is formed in two halves which may be drawn together by a cam and slot arrangement to engage and grip the periphery of a filter cartridge and provide removal torque.